Friday, January 14, 2005

Deploying distributed applications

Developing a strategy for application deployment is always hard. Every environment has its own characteristics. It's far easier to see the problem with popular applications that are installed by the end user. Custom applications are sometimes installed by an expert; sometimes the developer himself is available to do it. This helps to make the difficulty of this task to be greatly underestimated. The result is something that seasoned programmers will readily recognize: an installation that “should be a snap” takes many hours, or even days, to finish - and sometimes the developer just gives up as it discovers that the application, after all, was not ready for deployment. It's not enough to have the application working on the development environment.

Distributed applications bring this problem to a new level. The developer has now a lot of variables to predict; the interaction between the parts can have surprising results. It's not always obvious what is to best way to start up all the pieces, because they may exhibit circular dependencies. Bootstrapping a distributed application is much harder than installing a simple one.

I'm now writing code to 'bootstrap' one such application. It's a complex application that has several independent server processes communicating with XMLRPC. It's interesting to note how many issues pop up while doing it. For example: simple applications usually have a single test sequence. But distributed applications have to test combinations of components; they must fail gracefully when a server is not online. Some tests may require different combinations of servers, with different configurations. It's something that goes way beyond the features provided by the unittest module.

Starting the server in production mode is also a chore. It requires starting all individual servers, often in separate machines, all sharing some common configuration. This is an error prone task, specially if done manually. On the other hand, it's something difficult to automate because there are many things that can go wrong. At this point, I can only hope to get it right.

On a related note, I've found today a small gem: a Python library that encapsulates the Standard Windows Management Instrumentation framework. If you need it, check Tim Golden's wmi module. In my case, I had to download some updates from Microsoft to have WMI running on Win98. I'll post my experiences later when I finish testing it.

Are You an Advanced Marketer? Click here to learn how to broadcast thousands of messages directly to people's desktops with just a click from your mouse, Spam Free. Learn more about it here: making money on the internet site. It pretty much covers making money on the internet related stuff and it is FREE to join.

This is COOL...!!! Dear friends, Now you can help yourself take advantage of the huge frenzy of FREE advertising in your spare time, while in the comfort of your own home. Hook up NOW with this exiting program. Click here: FREE INFORMATION

Dear friends, Now you can help yourself take advantage of the huge surpluses of FREE advertising in your spare time, in the comfort of your own home. Hook up NOW with this exiting program. Click here: FREE INFORMATION

WATCH CAREFULLY...Here it is... FREE advertising, FREE download. No cost to you! Get your FREE download NOW! Make money and get FREE advertising! This is a great program for you to take advantage of... Check this out now for FREE!

Are You an Advanced Marketer? Click here to learn how to broadcast thousands of messages directly to people's desktops with just a click from your mouse, Spam Free. Learn more about it here: multi-level marketing site. It pretty much covers multi-level marketing related stuff and it is FREE to join.

Attention Blog Owners...!!! WARNING: A new immensely powerful viral marketing system has been released, which allows marketers to broadcast messages directly to people's desktops. Learn more about it here: home based business opportunity internet home business site. It pretty much covers home based business opportunity internet home business related stuff and it is FREE to join.

This is COOL...!!! Dear friends, Now you can help yourself take advantage of the huge frenzy of FREE advertising in your spare time, while in the comfort of your own home. Hook up NOW with this exiting program. Click here: FREE INFORMATION

Good morning, I don't know if for you is the same but I love the world where we live in, especially for the new technology and at the present time it sounds hard to me to stay without. The appliabces that I love the most are those things that I can keep in my pourse. As you are already presuming my mobile phone has an important role in my daily life. I can't resist to a new motorola ringtone. I change several of them a month so I feel the need to get a new one. The good part is I'm a student so my parents pay for them and further to buy a subscription is not difficult. Time to go back to study. Goodbye everyone Francine.

Dear friends, Now you can help yourself take advantage of the huge surpluses of FREE advertising in your spare time, in the comfort of your own home. Hook up NOW with this exiting program. Click here: FREE INFORMATION

Dear friend, Here is an opportunity for you that is taking over the internet. The compensation plan is second to none. The spill over will blow your mind and the educational products are of the highest quality. Knowledge is power and nobody can ever take that away from you. Join me in this business and see for yourself what you will be getting. Click here: FREE Information

Dear friends, Now you can help yourself take advantage of the huge surpluses of FREE advertising in your spare time, in the comfort of your own home. Hook up NOW with this exiting program. Click here: FREE INFORMATION

http://www.moneymakersecrets.com/firstmoneysecrets/ First Time To The Market work at home incomeEnjoy the opportunity, change your life -work at home income. Don't Miss work at home income - Visit Today...http://www.moneymakersecrets.com/firstmoneysecrets/

Quality assurance is implemented at the schematic design stage. Mansour Engineering’s quality assurance is an inclusive review of each discipline as well as an overall discipline coordination. Quality assurance procedures include analysis of the worst case scenario for verification of specific design parameters and for each discipline’s task. Project management overview integrates schedule and cost control into each and every aspect of design. Mansour Engineering project management objective is to develop a design that satisfies all requirements and is economically feasible to construct. To that end, cost estimating is within the preview and capabilities of each discipline project leader. Without sacrificing quality control or cost control, Mansour Engineering understands that scheduling is of the utmost importance. Mansour Engineering prepare a detailed timeline for each item on the project deliverable list and proceed on schedule by adjusting manpower activity to finish on time.

Earning money online never been this easy and transparent. You would find great tips on how to make that dream amount every month. So go ahead and click here for more details and open floodgates to your online income. All the best.

Earning money online never been this easy and transparent. You would find great tips on how to make that dream amount every month. So go ahead and click here for more details and open floodgates to your online income. All the best.